Cosmos/source/Cosmos.Debug.Symbols/SQL.cs

using Microsoft.Data.Sqlite;
using System;
using System.IO;
using System.Reflection;

namespace Cosmos.Debug.Symbols
{
    public class SQL
    {
        public readonly SqliteConnection Connection;

        public SQL(SqliteConnection aConnection)
        {
            Connection = aConnection;
        }

        public int? SelectOneInt(string aSql)
        {
            var xQry = Connection.CreateCommand();
            xQry.CommandText = aSql;
            return (int)xQry.ExecuteScalar();
        }

        public void Exec(string aSql)
        {
            var xQry = Connection.CreateCommand();
            xQry.CommandText = aSql;
            xQry.ExecuteNonQuery();
        }

        public void MakeUniqueInt(string aTable, string aCol, bool aAllowNulls)
        {
            string xIdxName = "Uq_" + aTable + "_" + aCol;
            if (aAllowNulls)
            {
                //http://sqlservercodebook.blogspot.com/2008/04/multiple-null-values-in-unique-index-in.html
                Exec("ALTER TABLE " + aTable + " ADD " + xIdxName + " AS (CASE WHEN " + aCol + " IS NULL THEN Id * -1 ELSE " + aCol + " END);");
                // We create index seperately instead of using unique keyword on previous SQL
                // so we can control name of the index for better identification
                Exec("CREATE UNIQUE INDEX Idx" + xIdxName + " ON " + aTable + "(" + xIdxName + ");");
            }
            else
            {
                Exec("CREATE UNIQUE INDEX Idx" + xIdxName + " ON " + aTable + "(" + aCol + ");");
            }
        }

        public void MakeIndex(string aTable, string aCol, bool aUnique)
        {
            Exec("CREATE " + (aUnique ? "UNIQUE " : "") + "INDEX Idx_" + aTable + "_" + aCol + " ON " + aTable + "(" + aCol + ");");
        }

        public void MakeUniqueString(string aTable, string aCol, bool aAllowNulls)
        {
            string xIdxName = "Uq_" + aTable + "_" + aCol;
            if (aAllowNulls)
            {
                Exec("ALTER TABLE " + aTable + " ADD " + xIdxName + " AS (CASE WHEN " + aCol + " IS NULL THEN 'key-' + CAST([Id] as varchar(10)) ELSE UPPER(RTRIM(LTRIM(" + aCol + "))) END);");
                Exec("CREATE UNIQUE INDEX Idx" + xIdxName + " ON " + aTable + "(" + xIdxName + ");");
            }
            else
            {
                Exec("CREATE UNIQUE INDEX Idx" + xIdxName + " ON " + aTable + "(" + aCol + ");");
            }
        }

        internal void CreateDB()
        {
            ExecuteAssemblyResource("SQLite.sql");
        }

        /// <summary>
        /// Exceutes SQL file stored inside assembly.
        /// </summary>
        /// <param name="resourceName">Name of the assembly resource to execute.</param>
        internal void ExecuteAssemblyResource(string resourceName)
        {
            resourceName = GetType().GetTypeInfo().Assembly.GetName().Name + "." + resourceName;

            using (var strm = typeof(SQL).GetTypeInfo().Assembly.GetManifestResourceStream(resourceName))
            {
                if (strm == null)
                {
                    throw new Exception("Sql resource not found!");
                }
                using (var reader = new StreamReader(strm))
                {
                    Exec(reader.ReadToEnd());
                }
            }
        }
    }
}